Versatile blind stitch sewing machine

ABSTRACT

A versatile blind stitch sewing machine which comprises a power source, pulleys, an upper shaft, work feed means, needle rocking means, a lower shaft casing, work holding-down means and work support means in which the work holding-down means includes a work holding-down member provided on the undersurface with an inverted V-shaped groove and the work support means includes a work support member having a complementary inverted V-shaped tip end and adapted to move toward and away from the work holdingdown member so as to vary the clearance therebetween through which a work to be stitched passes.

United States katem [191 Matsumoto et a1.

VERSATILE BLIND STITCH SEWING MACHINE Inventors: Mitsuo Matsumoto, Tokyo;

Yoshihide Nishizuka; Teruo lwata, both of Osaka, all of Japan Nara Sewing Machine Industrial Co., Ltd., Tokyo, Japan Filed: Nov. 26, 1971 Appl. No.: 202,396

Assignee:

Foreign Application Priority Data Nov. 28, 1970 Japan 45/117740 Nov. 28, 1970 Japan 45/117741 US. Cl. 112/178, 112/212 Int. Cl D05b 1/24 Field of Search 112/140, 148, 153,

References Cited UNITED STATES PATENTS 7/1941 Dearborn 112/178 2,658,464 1l/1953 Greco 112/178 2,751,870 6/1956 Buono 112/198 X Primary Examiner-Werner H. Schroeder AttorneyE. F. Wenderoth et a1.

[57] ABSTRACT A versatile blind stitch sewing machine which comprises a power source, pulleys, an upper shaft, work feed means, needle rocking means, a lower shaft casing, work holding-down means and work support means in which the work holding-down means includes a work holding-down member provided on the undersurface with an inverted V-shaped groove and the work support means includes a work support member having a complementary inverted V-shaped tip end and adapted to move toward and away from the work holding-down member so as to vary the clearance therebetween through which a work to be stitched passes.

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MOMMLW W ATTORNEY S PAWNFEU MIT SUO MATSUMOTO YOSH IH IDE NISHIZUKA and TERUO IWATA INVENTORS ATTORNEY S I VERSATILE BLIND STITCH SEWING MACHINE BACKGROUND OF THE INVENTION This invention relates to an improved blind stitch sewing machine which can be employed for various blind stitch modes such as plain blind stitch, hemstitch, fold-stitch and tuck-stitch without the need for changing attachments such as a needle plate, a work support member and a work holding-down member and which is of a small size suitable to be employed on a domestic machine.

Conventional blind stitch sewing machines have been so far predominantly employed among professional tailors. Most of the conventional blind stitch sewing machines have been employed for any one of the different stitches such as plain blind stitch, hemstitch, foldstitch, tuck-stitch, etc. because such conventional stitch sewing machines lack versatility in operation and function and have exhibited their full efficiency as onestitch machines. These conventional blind stitch sewing machines can, of course, be employed as versatile blind stitch sewing machines by rechanging their attachments such as needle plates, work holding-down members, work feed members and the like depending upon the particular stitch mode desired, but such changing of attachments is usually time consuming work, even if performed by skilled workers, and is almost impossible for laymen to carry out. Therefore, it has been generally considered that one blind stitch sewing machine can be, in principle, employed for only one kind of stitch.

Thus, when it is desired or necessary to perform different stitches such as plain stitch, hemstitch, nodestitch and tuck-stitch it becomes necessary to produce different types of blind stitch sewing machines, each of which is pre-designed to perform only one particular kind of blind stitch. However, some professional tailors and most housewives cannot afford to do this or do not have the space for several machines. Such people have long desired a compact, portable and versatile blind stitch sewing machine which can perform different kinds of blind stitches without the necessity for complicated and time-consuming changing of parts.

SUMMARY OF THE INVENTION This invention relates to a blind stitch sewing machine, and more particularly, to a novel and improved blind stitch sewing machine. The machine of this invention is distinguished from the conventional blind stitch sewing machines designed to perform exclusively one particular stitch in that it can make different kinds of stitches such as plain stitch, hemstitch, fold-stitch, tuck-stitch, etc. without the necessity for changing attachments such as the needle plate, work support member, work holding-down member and other parts. In the conventional blind stitch sewing machine, the fulcrum for the shaft of the feeder base is machined in the arm body and the needle plate mounting which is secured to the arm body adjacent to the feeder base shaft fulcrum is also directly machined inthe arm body and therefore, with such arrangement of the shaft fulcrum and presser foot mounting, if the size of the arm head is reduced, a proper relative position for normal work feeding operation can not be set. Thus, it has been impossible to reduce the size of the machine body as desired. To overcome the above difiiculty inherent in the conventional blind stitch sewing machine, the present 2 invention incorporates improved work feed means with which it is possible to vary the size of the arm head and accordingly, vary the overall size of the machine.

Therefore, one major object of the present invention is to provide a versatile blind stitch sewing machine comprising a novel and improved work gripping device by means of which the machine can perform different blind stitches such as plain stitch, hemstitch, foldstitch, tuck-stitch, etc. without need for changing the needle plate, work support member, presser foot and the like parts.

Thus, one object of the present invention is to provide a versatile blind stitch sewing machine which can perform different kinds of stitches and yet is light and compact enough to be easily carried about.

Another object of the present invention is to provide a blind stitch sewing machine which is characterized in that a lower shaft casing having a work support member separate from but adapted to contact a work holding-down member is pivoted to the machine body arm which is normally urged in one direction, a pin having a flattened portion in its periphery being rotatably mounted on the lower shaft casing and a switching mechanism being provided for urging the flattened portion of the pin against boss means provided in the machine body.

A still further object of the present invention is to provide a blind stitch sewing machine the arm of which has a relatively small size head, the body of the arm having a bearing pedestal mounted thereon, the socalled work feed mechanism including the crank, needle plate and the like being supported on the pedestal whereby the overall size of the machine body is reduced.

The above and other objects and attendant advantages of the present invention will be more readily apparent to those skilled in the art from a reading of the following detailed description of the invention in conjunction with the accompanying drawings which show one preferred embodiment of the invention only for illustration and not for limiting the scope of the invention in any way;

. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of one preferred embodiment of a versatile blind stitch sewing machine of the invention with portion thereof broken away;

FIG. 2 is a top plan view of the sewing machine of FIG. 1;

FIG. 3 is an end elevational view of the sewing machine as seen on the right-hand side of FIG. 1;

FIG. 4 is an end elevational view of the sewing machine as seen on the left-hand side of FIG. 1;

FIG. 5 is a fragmentary perspective view of the work holding-down means device;

FIG. 6 is a front elevational view showing cooperative relationship between the work holding-down member and work support member of the work gripping arrangement of FIG. 5;

FIG. 7 is a side elevational view of FIG. 6;

FIGS. 8A, 8B and 8C are views showing the work holding-down and work support members in various operative positions for performing different stitch modes;

FIG. 9 is a side elevational view in partial section of the selective switching mechanism for the work support member with portion thereof broken away;

FIG. is a front elevational view of the selective switching mechanism of FIG. 9;

FIGS. 11A and 11B are sectional views showing the switching mechanism of FIG. 9 in different operative positions for performing different stitches;

FIG. 12 is a top plan view of work feed means with a portion thereof broken away;

FIG. 13 is a side elevational view of the work feed means of FIG. 12;

FIG. 14 is a cross-sectional view taken substantially along the line XIV XIV of FIG. 13; and

FIG. 15 is a view showing the mounting of the bearing pedestal on the arm body.

PREFERRED EMBODIMENT OF THE INVENTION The present invention will now be described referring to the accompanying drawings which illustrate one preferred embodiment of the invention. The versatile blind stitch sewing machine of the invention is identified as a whole by reference numeral 20. As seen in FIGS. 1 through 4 inclusive, the sewing machine is not different from the conventional blind stitch sewing machine so far as the sewing machine 20 comprises a power source pulley 21, a power transmission pulley 22, and upper shaft 23 (FIGS. 12 and 13), a work feed device 24, a needle rocking device 25, a lower shaft casing 26, a work gripping device 27, a work support device 28 and other conventional parts. The versatile blind stitch sewing machine 20 of the invention is distinguished from the conventional stitch sewing machines primarily in the provision of the novel work gripping arrangement 27.

Description will be now had on the work holding -down means 27 of the invention referring to FIGS. 5 through 8 inclusive.

In the work holding-down means 27, a mounting block 32 is secured to a needle plate 30 by means of a set screw 31 and one end of a mounting stub shaft 33 is fitted in and extends through an opening in the mounting block 32. The other end of the stub shaft 33 has a work holding-down member 35 secured by means of a set screw 34. The mounting block 32 has on the side opposite the work holding-down member 35 a spring support member 36 secured by means of a set screw 37 which secures the stub shaft 33 and spring support member 36 together. Thus, the stub shaft 33 is prevented from moving in its axial direction and the work holding'down member 35 is always subjected to a constant pressure from a spring which will be described hereinbelow. A horizontal threaded bar 36' extends between the spring support member 36 with one end extending through and threadably received in the member 36 and an upright member of the needle plate 30, and a tension spring 38 is mounted on the bar 36 with one end secured to a pin 40 extending upwardly from the upright member of the needle plate 30, the other end of the spring 36 being anchored to the threaded bar 36. The extention of the threaded bar 36 has a manual adjusting screw 39 which is in thread engagement with the threaded bar whereby the tension on the spring 38 is adjusted by turning the adjusting screw 39 in one or the other direction. Thus, the work holding-down member 35 and a work support member 41 positioned under the holding-down member are adapted to be held in contact with each other by the action of the tension spring 38 under normal conditions whereby a sewing operation can be performed with a work clamped between the work holding-down and support members.

According to the present invention, the undersurface of the work holding-down member 35 is provided with a work receiving groove having a substantially inverted V-shape in cross section and the groove has opposite inclined surfaces 35a and 35b which respectively extend substantially in parallel to the opposite surfaces of the upper or tip end of the work support member 41 which has a mating inverted V-shaped cross section. The surface 35b is longer than the surface 350 and thereby provides an escape 35c for the work. With the above construction and arrangement of the work holding-down and support members 35 and 41, the work to be stitched is allowed to escape into the escape 350 as it is stitched which may be necessary or desired depending upon the particular stitch selected.

The versatile blind stitch sewing machine of the invention comprising the improvements to be referred to hereinbelow can be operated for different stitches such as plain blind stitch (FIG. 8A), single folded blind (FIG. 8B) and double folded blind stitch (FIG. 8C), for example.

In changing the operation of the sewing machine of the invention over from one kind of stitch to another, according to the present invention, it is not necessary to change any part such as the needle plate, work holding-down member, work support member and other attachments of the sewing machine. Accordingly, the sewing machine of this invention can be easily and speedily adapted for different kinds of stitches and, therefore, is economical and practical to use for various stitch sewing purposes.

In FIGS. 9 through 11 inclusive, there is shown a switching mechanism which permits a lower shaft casing 26 to pivot about an axis so as to move the work support member toward or away from the work holding-down member whereby the sewing machine can be operated for different stitches.

As seen in FIGS. 9 11 inclusive, the lower shaft casing 26 is mounted on the arm 43 of the machine body by means of a shaft or pivot pin 42 for pivotal movement about the shaft and is normally urged to rock in the arrow direction or clockwise direction 45 by the action of spring 44. The pivotal movement of the lower shaft casing 26 in the arrow direction is limited by boss means including a bolt 46 and a nut 47 which are secured to the arm 43. A pin 48 is fitted in an opening 49 (FIG. 9) in the lower shaft casing 26 and adapted to contact the bolt 46. A knob 51 for manual adjustment is fixedly mounted at one end of the pin 48 by means of a set bolt 50 and when the knob is manually turned in one direction a predetermined angular distance, a flattened portion 48a machined in the pin 48 engages bolt 46 whereby the work support member 41 is caused to contact the work holding-down member 35. And as seen in FIG. 11B, when the knob 51 is turned in the opposite direction until the circular periphery of the pin 48 other than the flattened portion 48a contacts the bolt 46, the lower shaft casing 26 is pivoted downwardly by a small distance corresponding to the depth of the flattened portion 48a thereby to separate the work support member 41 from the work holding-down member 35 by a small distance whereupon the machine is prepared for a different kind of stitch. A steel ball 53 is elastically received in a small hole 52 machined in the lower shaft casing 26 by means of a spring 54 which is also received in the hole 52 and normally urges the steel ball outwardly. The purpose of the steel ball and spring arrangement 53 and 54 is, through the yielding contact of steel ball 53 with knob 51, to hold the knob in position and to prevent knob 51 from inadvertently or freely rotating during the operation of the sewing machine.

As is clear from the foregoing description, according to the present invention, when the lower shaft casing 26 is pivoted about the pin 42 in the clockwise direction until the flattened portion 48a on the pin 48 abuts against the bolt 46 on the lower shaft casing 26, the work support member 41 contacts the work holdingdown member 35 and the sewing machine is ready conditioned for plain blind stitching. On the other hand, when the lower shaft casing 26 is pivoted bout the shaft 42 in the opposite or counter-clock direction until the flattened portion 48a on the pin 48 separates from its abutment engagement with the bolt to allow the other periphery of the pin 48 to contact the bolt 46 so as to leave a slight space between the work support and work holding-down members 41 and 35, the sewing machine is made ready conditioned for blind folded edge stitch. Thus, it will be understood that the blind stitch sewing machine can be employed for different kinds of stitches without need for changing a part or parts as is necessary in the conventional blind stitch sewing machines when changing from one kind of stitch to another.

FIGS. 12 through inclusive show the mounting of the bearing pedestal on the arm body of the machine. The provision of the mounting is to reduce the size of the machine as much as possible.

As shown in FIG. 15, the arm body 60 which constitutes the machine body is provided on the underside with a stepped recess or pedestal seat 61 and a complementally shaped bearing pedestal 62 is received in and secured to the seat 61 by means of set bolts. The bearing portion 64 of the pedestal 62 has a transverse shaft 65 received and held in position therein and one end of the shaft 65 freely mounts one arm 66 of a crank thereon. The other arm of the crank is connected through an eccentric pin 69 to one end of the pedestal 68 the other end of which is connected to an eccentric drive 67. A work feed pawl 70 is secured to the pedestal 68 by means of set screws 71 and the abovementioned needle plate 30 is also secured to a feeder base 68 by means of set screws 72.

As is clear from the foregoing detailed description of one preferred embodiment of the invention, the present invention provides an improved versatile blind stitch sewing machine which can be employed for various blind stitches without the need necessity for changing attachments and is light and compact enough to be easily carried about.

in the conventional blind stitch sewing machines the fulcrum for the pedestal shaft and needle plate mounting are machined in the arm body. in contrast, according to the present invention, since the separate bearing pedestal is mounted on the arm body and the work feed mechanism including the work support table, crank and needle plate is mounted on the bearing pedestal, the arm head can be varied in length and, when desired, the overall size of the blind stitch sewing machine of the invention can be reduced accordingly.

While there has been described what is at present considered to be the preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is aimed, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

l. A blind stitch sewing machine comprising a power source, pulleys, an upper shaft, work feed means, needle rocking means, a lower shaft causing, work holdingdown means and work support means, said work support means having a work support member on said lower shaft casing and having an inverted V-shaped tip end, and said holding down means has a work holdingdown member having in the undersurface thereof a V- shaped groove complementary in shape and opposed to said V-shaped tip and having oppositely inclined surfaces substantially parallel to said tip of the work support member, said work holding-down member having a work insertion recess therein at the apex of said groove into which one of the inclined surfaces extends beyond the upper end of the other inclined surface so as to define the work insertion recess for receiving a portion of the work to be stitched.

2. A blind stitch sewing machine as claimed in claim 1 in which said lower shaft casing having the work support member thereon is pivoted to the sewing machine and said machine includes means normally urging said work support member in one pivotal direction, and a position adjusting mechanism for said work support member comprising a rotatable pin having a flattened portion on the periphery thereof and a threaded adjustable pin, the end of the threaded adjustable pin and the periphery of the rotatable pin being urged against each other, one of said pins being in the machine and other pin being on the work support member, whereby the distance between said work support member and work holding-down member can be adjusted. 

1. A blind stitch sewing machine comprising a power source, pulleys, an upper shaft, work feed means, needle rocking means, a lower shaft causing, work holding-down means and work support means, said work support means having a work support member on said lower shaft casing and having an inverted V-shaped tip end, and said holding down means has a work holding-down member having in the undersurface thereof a V-shaped groove complementary in shape and opposed to said V-shaped tip and having oppositely inclined surfaces substantially parallel to said tip of the work support member, said work holding-down member having a work insertion recess therein at the apex of said groove into which one of the inclined surfaces extends beyond the upper end of the other inclined surface so as to define the work insertion recess for receiving a portion of the work to be stitched.
 2. A blind stitch sewing machine as claimed in claim 1 in which said lower shaft casing having the work support member thereon is pivoted to the sewing machine and said machine includes means normally urging said work support member in one pivotal direction, and a position adjusting mechanism for said work support member comprising a rotatable pin having a flattened portion on the periphery thereof and a threaded adjustable pin, the end of the threaded adjustable pin and the periphery of the rotatable pin being urged against each other, one of said pins being in the machine and other pin being on the work support member, whereby the distance between said work support member and work holding-down member can be adjusted. 